Theorizing lesson study: Integration of action research methodology in Japanese lesson study approach

Global challenges faced by teacher researchers outside of Japan are related to theoretical, practical knowledge, research methodology, success and sustainability of adapted lesson study (LS) projects. These issues highlight the necessity of in-depth theoretical research of authentic Japanese lesson study (JLS) approach. The purpose of the article is to explore LS theorization through theoretical analysis of multifaceted structure of JLS components and integration of action research (AR) methodology in JLS to make LS evidencebased and comprehensible. The main idea is theorization of LS through modeling, evaluation checklist and conceptualization of LS philosophy. As a result of comparative, analysis and synthesis, structured analysis and modeling research methods, multi cyclical LS model integrated with AR methodology, evaluation checklist used as assessment tool for model realization and LS philosophy were developed. The model and checklist are used to describe 4 LS as AR stages (pre-diagnostic, intervention, post-diagnostic and knowledge construction) and 37 components. The model is significant to get theoretical knowledge acquisition, the evaluation checklist is crucial in practice as self-correction, self-assessment and self-regulation tool. They can be utilized by teachers throughout LS process. The research findings contribute to developing LSmethodology with a set of assessment criteria to make LS scientifically grounded research.